Properties and action mechanisms of intravenous gammaglobulin

Resumen

Intravenous immunoglobulins (IVIG) preparations have been used as a substitutive therapy for primary and secondary immunodeficiencies for many years; now it is well know that IVIG can have two other important and opposite functions: pro and anti-inflammatory, depending on its concentration. Low doses of IVIG exert proinflammatory activities, that require complement activation or binding via Fc fragment of IgG to IgG Fcγ specific receptors present on effector cells of innate immunity. On the other hand, administration of high IVIG doses has anti-inflammatory activity. This manuscript presents a revision of how IVIG IgG mediated this effects, how and upon which cells from the immune system acts, their capacity to scavenging complement fragments, the recently demonstrated anti-inflammatory activity of variable minor sialylated portion of IgG molecules and finally, the importance of genetic variation and expression of Fcγ receptors. To comprehend the mechanism of action of IVIG is fundamental, not only to obtain further improvements on therapeutic effectiveness, but also to discover new and unexpected capacities of this biological bomb known as IVIG.